1. Chapter 12 Population and Urbanization Key Terms

2. demography A subspecialty within sociology that focuses on the study of human populations, with particular emphasis on their size and rate of growth. birth rate The annual number of births per every 1,000 people in a designated area.

3. age-specific birth rate The annual number of births per every 1,000 women of a specific age group. fertility rate The average number of children that women in a specific population bear over a lifetime.

4. crude death rate The annual number of deaths per every 1,000 people in a designated area. infant mortality rate The death rate among those one year old or younger.

5. population pyramid A series of horizontal bar graphs, each of which represents a different five-year age cohort. cohort A group of people who share a common characteristic or life event.

6. expansive pyramids Population pyramids that are broadest at the base with each successive bar smaller than the one below it, showing that the population is increasing in size and composed disproportionately of young people.

7. constrictive pyramids Population pyramids that are narrower at the base than in the middle, showing that the population is composed disproportionately of middle-aged and older people.

8. stationary pyramids Population pyramids in which all age cohorts in the population are roughly the same size. migration rate The difference between the number of people entering and the number of people leaving a designated geographical area in a year.

9. push factors Conditions that encourage people to move out of an area. pull factors Conditions that encourage people to move into an area.

10. emigration The departure of individuals from a country. immigration The entrance of individuals into a new country.

11. internal migration The movement within the boundaries of a single country- from one state, region, or city within a country to another. in-migration The movement of people into a designated area.

12. out-migration The movement of people out of a designated are. natural increase The number of births minus the number of deaths occurring in a year.

13. rate of natural increase The number of births minus the number of deaths occurring in a year divided by the size of a population at the beginning of the year. doubling time The estimated number of years required for a country’s population to double in size.

14. mortality crisis A violent fluctuation in the death rate caused by war, famine or epidemic. positive checks Events that increase mortality, including epidemics of infectious and parasitic disease, war, and famine.

15. demographic gap The difference between birth rates and death rates. urbanization An increase in the number of cities and growth in the proportion of the population living in cities.

16. labor-intensive poor economies Countries that differ markedly from industrialized countries on indicators such as doubling time, infant mortality, total fertility, per capita income, and annual per capita consumption of energy. core economies The wealthiest, most highly diversified economies in the world.

17. demographic trap The point at which population growth overwhelms the environment's carrying capacity. externality costs Costs that are not figured into the price of a product but that are nevertheless a price we pay for using or creating a product.

18. mega city An urban agglomeration with 8 million or more people. urban agglomeration An urban area that includes a central city and neighboring communities linked to it by continuous built-up areas or many communities.

19. Metropolitan Statistical Area (MSA) One or more cities with an least 50,000 residents surrounded by densely populated countries. central city The largest city within a metropolitan statistical area.

20. suburb An urban area outside the political boundaries of a city. nonmetropolitan Geographical areas beyond the political boundaries of a central city and its suburbs.